Comparison of Mesenchymal Stem Cell Efficacy in Ischemic Versus Nonischemic Dilated Cardiomyopathy

Therapeutic effect of N, N-Diphenyl-1,4-phenylenediamine and adipose-derived stem cells coadministration on diabetic cardiomyopathy in type 1 diabetes mellitus-rat model

Type 1 diabetes stem-cell-based treatment approach is among the leading therapeutic strategies for treating cardiac damage owing to the stem cells' regeneration capabilities. Mesenchymal stem cells derived from adipose tissue (AD-MSCs) have shown great potential in treating diabetic cardiomyopathy (DCM). Herein, we explored the antioxidant-supporting role of N, N'-diphenyl-1,4-phenylenediamine (DPPD) in enhancing the MSCs' therapeutic role in alleviating DCM complications in heart tissues of type 1 diabetic rats. Six male albinos Wistar rat groups have been designed into the control group, DPPD (250 mg/kg, i.p.) group, diabetic-untreated group, and three diabetic rat groups treated with either AD-MSCs (1 × 106 cell/rat, i.v.) or DPPD or both. Interestingly, all three treated diabetic groups exhibited a significant decrease in serum glucose, HbA1c, heart dysfunction markers (lactate dehydrogenase and CK-MP) levels, and lipid profile fractions (except for HDL-C), as well as some cardiac oxidative stress (OS) levels (MDA, AGEs, XO, and ROS). On the contrary, serum insulin, C-peptide, and various cardiac antioxidant levels (GSH, GST, CAT, SOD, TAC, and HO-1), beside viable cardiac cells (G0/G1%), were markedly elevated compared with the diabetic untreated group. In support of these findings, the histological assay reflected a marked enhancement in the cardiac tissues of all diabetic-treated groups, with obvious excellency of the AD-MSCs + DPPD diabetic-treated group. Such results strongly suggested the great therapeutic potentiality of either DPPD or AD-MSCs single injection in enhancing the cardiac function of diabetic rats, with a great noted enhancement superiority of DPPD and AD-MSCs coadministration.

Prospective randomized controlled trial of the safety and feasibility of a novel mesenchymal precursor cell therapy in hypoplastic left heart syndrome

Objective

To assess the safety and feasibility of low-dose, novel, allogenic mesenchymal precursor cell (MPC) therapy as an adjunct to left ventricular (LV) recruitment for patients with hypoplastic left heart syndrome (HLHS) and borderline left ventricles. MPC injections into the hypoplastic left ventricle may stimulate neovascularization and beneficial LV remodeling and may improve the likelihood of achieving biventricular (BiV) or 1.5 ventricle (1.5V) circulation.

Methods

Children <5 years with prior single ventricle palliation undergoing LV recruitment surgery at a single center were randomized to MPC injections into the LV endocardium/papillary muscles (MPCs) or standard-of-care (controls) and followed for 24 months. The primary endpoint was safety, including (serious) adverse events (S/AEs), and panel reactive antibodies (PRAs). Secondary endpoints included BiV/1.5V conversion and LV size and function.

Results

Nineteen subjects were enrolled, including 9 MPC recipients and 10 controls. Fourteen patients (74%) had >1 AE, and 2 patients had SAEs, both deemed unrelated to the trial product. AE severity and frequency were similar in the 2 groups. Baseline PRA levels were high, with no difference between the groups at 12 months. The overall probability of BiV/1.5V conversion was 0.16 (95% confidence interval [CI], 0.05 to 0.41) at 12 months and 0.52 (95% CI, 0.31 to 0.77) at 24 months. For patients with imaging data at both time points, increases in LV volumes from baseline to 12 months were larger in the MPC group by 3-dimensional echocardiography and cardiac magnetic resonance imaging. For children who successfully underwent BiV conversion (n = 12), full BiV conversion was achieved at 24 months in 5 of 5 (100%) MPC-treated children compared with 4 of 7 (57%) controls.

Conclusions

MPC injections were considered safe and feasible in HLHS patients. More than 50% of subjects underwent BiV/1.5V conversion within 2 years. Larger trials are needed to investigate the therapeutic potential of MPCs in this population.

The Molecular Role of Immune Cells in Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is a rare and severe condition characterized by chamber dilation and impaired contraction of the left ventricle. It constitutes a fundamental etiology for profound heart failure and abrupt cardiac demise, rendering it a prominent clinical indication for heart transplantation (HTx) among both adult and pediatric populations. DCM arises from various etiologies, including genetic variants, epigenetic disorders, infectious insults, autoimmune diseases, and cardiac conduction abnormalities. The maintenance of cardiac function involves two distinct types of immune cells: resident immune cells and recruited immune cells. Resident immune cells play a crucial role in establishing a harmonious microenvironment within the cardiac tissue. Nevertheless, in response to injury, cardiomyocytes initiate a cytokine cascade that attracts peripheral immune cells, thus perturbing this intricate equilibrium and actively participating in the initiation and pathological remodeling of dilated cardiomyopathy (DCM), particularly during the progression of myocardial fibrosis. Additionally, immune cells assume a pivotal role in orchestrating the inflammatory processes, which are intimately linked to the prognosis of DCM. Consequently, understanding the molecular role of various immune cells and their regulation mechanisms would provide an emerging era for managing DCM. In this review, we provide a summary of the most recent advancements in our understanding of the molecular mechanisms of immune cells in DCM. Additionally, we evaluate the effectiveness and limitations of immunotherapy approaches for the treatment of DCM, with the aim of optimizing future immunotherapeutic strategies for this condition.

Young human PRP promotes the rejuvenation of aged bone marrow mesen -chymal stem cells and the therapeutic effect on ischemic heart disease

Bone marrow mesenchymal stem cell (BMSC) transplantation is an effective treatment for ischemic heart disease, but its effectiveness is limited in aging populations due to decreased viability and injury resistance of autologous BMSCs. The purpose of this study was to compare the differences between platelet-rich plasma (PRP) derived from young and aged donors, and to investigate whether it is possible to enhance the viability of elderly human BMSCs (hBMSCs) using PRP, and to apply the rejuvenated hBMSCs for the treatment of ischemia. The key growth factors in PRP, including IGF-1, EGF, and PDGF-BB, were found to have significant differences between young and old individuals. Our results showed that PRP could enhance the proliferation, cloning, and rejuvenation of aged hBMSCs, with a superior effect observed when using PRP derived from younger donors. In the SD rat infarct model, the application of hBMSCs optimized with PRP resulted in a smaller infarct area compared to the control group (NC-Old). Specifically, the infarct area in the group treated with hBMSCs cultured with PRP from young donors (YPRP-Old) was smaller than that in the group treated with PRP from older donors (OPRP-Old). The survival rate of hBMSCs after transplantation, the number of neovascularization in the infarct area of SD rats and the recovery of cardiac function were all higher in the YPRP-Old group than the OPRP-Old group, and both groups were better than the group treated with aged hBMSCs alone. In conclusion, PRP may provide a new stem cell transplantation therapy option for ischemic diseases.

m6A RNA methylation modification is involved in the disease course of heart failure

We explored N⁶-methyladenosine (m6A) RNA methylation as one of the gene regulatory mechanisms in heart failure (HF) biology. Understanding the different physiological mechanisms will facilitate the prevention and individualized treatment of HF. The Gene Expression Omnibus (GEO) database served as the source of the data. In GSE116250, differential analysis between ischemic cardiomyopathy (ICM), dilated cardiomyopathy (DCM) and controls yielded differentially expressed m6A regulators. Differential analysis between HF and controls in GSE131296 identifies m6A-modified genes and then performs enrichment analysis. Protein-protein interaction (PPI) network analysis was performed for the differentially expressed ICM- or DCM-associated genes in GSE116250 and GSE55296, respectively. Finally, the diagnostic genes for ICM and DCM were predicted using receiver operating characteristic (ROC) curve. YTHDC1, HNRNPC and HNRNPA2B1 were significantly downregulated in GSE116250 in DCM and ICM compared with controls. A total of 195 genes were identified in GSE131296 as subject to m6A alteration. These genes may play a role in HF through the MAPK signaling pathway and p53 signaling pathway. PPI network analysis identified CCL5, CXCR4 and CCL2 as key genes for ICM and IL-6 as a key gene for DCM. Through ROC curves, we identified m6A-modified APLP1, KLF2 as potential diagnostic genes for ICM, and m6A-modified FGF7, FREM1 and C14orf132 as potential diagnostic genes for DCM. Our findings support m6A modifying mechanisms in HF etiology that contribute to the treatment of HF. Thus, our data suggest that m6A methylation may be an interesting target for therapeutic intervention.

Nano-Messengers of the Heart: Promising Theranostic Candidates for Cardiovascular Maladies

Till date, cardiovascular diseases remain a leading cause of morbidity and mortality across the globe. Several commonly used treatment methods are unable to offer safety from future complications and longevity to the patients. Therefore, better and more effective treatment measures are needed. A potential cutting-edge technology comprises stem cell-derived exosomes. These nanobodies secreted by cells are intended to transfer molecular cargo to other cells for the establishment of intercellular communication and homeostasis. They carry DNA, RNA, lipids, and proteins; many of these molecules are of diagnostic and therapeutic potential. Several stem cell exosomal derivatives have been found to mimic the cardioprotective attributes of their parent stem cells, thus holding the potential to act analogous to stem cell therapies. Their translational value remains high as they have minimal immunogenicity, toxicity, and teratogenicity. The current review highlights the potential of various stem cell exosomes in cardiac repair, emphasizing the recent advancements made in the development of cell-free therapeutics, particularly as biomarkers and as carriers of therapeutic molecules. With the use of genetic engineering and biomimetics, the field of exosome research for heart treatment is expected to solve various theranostic requirements in the field paving its way to the clinics.

Comparative analysis of LVAD patients in regard of ischaemic or idiopathic cardiomyopathy: A propensity-score analysis of EUROMACS data

BACKGROUND

Despite recent advances in management of patients with advanced heart failure, mortality remains high. Aim of this study was to compare impact of different aetiology of ischaemic and idiopathic cardiomyopathy on early outcomes and long-term survival of patients after left ventricular assist device implantation.

METHODS

European Registry for Patients with Mechanical Circulatory Support (EUROMACS) gathers clinical data and follow-up parameters of LVAD recipients. Patients enrolled in the EUROMACS registry with primary diagnosis of either ischaemic (n = 1190) or idiopathic (n = 812) cardiomyopathy were included. Primary Endpoints were early mortality as well as long-term survival. Secondary endpoint were major postoperative adverse events, such as need for rethoracotomy. Additionally, a propensity-score matching analysis was performed for patients with ischaemic (n = 509) and idiopathic (n = 509) cardiomyopathy.

RESULTS

In terms of basic demographics and baseline parameters the two groups significantly differed as expected before propensity-score matching due to different aetiology of cardiomyopathy. Seven-day (52 (4.4%) versus 18 (2.2%); p = 0.009), 30-day (153 (12.9%) versus 73 (9.0%); p = 0.008) and in-hospital mortality (253 (19.7%) versus 123 (15.1%); p = 0.009) were significantly lower in the idiopathic cardiomyopathy group compared to the ischaemic cardiomyopathy group, whereas after propensity-score matching 30-day (p = 0.169) was comparable and in-hospital mortality (p = 0.051) was almost significant. Kaplan-Meier survival analysis revealed no significant difference in regard of long-term survival after propensity-score matching (Breslow-test p = 0.161 and LogRank-test p = 0.113).

CONCLUSION

Though patients with ischaemic and idiopathic cardiomyopathy suffer from different cardiomyopathy aetiologies, 30-day-mortality and long-term survival of both groups were similar leading to the conclusion that covariates predominately influence mortality and survival of ischaemic and idiopathic cardiomyopathies.

Identification of cardiomyopathy-related core genes through human metabolic networks and expression data

Background

Cardiomyopathy is a complex type of myocardial disease, and its incidence has increased significantly in recent years. Dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) are two common and indistinguishable types of cardiomyopathy.

Results

Here, a systematic multi-omics integration approach was proposed to identify cardiomyopathy-related core genes that could distinguish normal, DCM and ICM samples using cardiomyopathy expression profile data based on a human metabolic network. First, according to the differentially expressed genes between different states (DCM/ICM and normal, or DCM and ICM) of samples, three sets of initial modules were obtained from the human metabolic network. Two permutation tests were used to evaluate the significance of the Pearson correlation coefficient difference score of the initial modules, and three candidate modules were screened out. Then, a cardiomyopathy risk module that was significantly related to DCM and ICM was determined according to the significance of the module score based on Markov random field. Finally, based on the shortest path between cardiomyopathy known genes, 13 core genes related to cardiomyopathy were identified. These core genes were enriched in pathways and functions significantly related to cardiomyopathy and could distinguish between samples of different states.

Conclusion

The identified core genes might serve as potential biomarkers of cardiomyopathy. This research will contribute to identifying potential biomarkers of cardiomyopathy and to distinguishing different types of cardiomyopathy.

Mesenchymal Stem Cell Therapy in Diabetic Cardiomyopathy

The incidence and prevalence of diabetes mellitus (DM) are increasing worldwide, and the resulting cardiac complications are the leading cause of death. Among these complications is diabetes-induced cardiomyopathy (DCM), which is the consequence of a pro-inflammatory condition, oxidative stress and fibrosis caused by hyperglycemia. Cardiac remodeling will lead to an imbalance in cell survival and death, which can promote cardiac dysfunction. Since the conventional treatment of DM generally does not address the prevention of cardiac remodeling, it is important to develop new alternatives for the treatment of cardiovascular complications induced by DM. Thus, therapy with mesenchymal stem cells has been shown to be a promising approach for the prevention of DCM because of their anti-apoptotic, anti-fibrotic and anti-inflammatory effects, which could improve cardiac function in patients with DM.

OUP accepted manuscript

Background

Left ventricular hypertrophy and heart failure with preserved ejection fraction (HFpEF) are primary manifestations of the cardiorenal syndrome in patients with chronic kidney disease (CKD). Therapies that improve morbidity and mortality in HFpEF are lacking. Cell-based therapies promote cardiac repair in ischemic and non-ischemic cardiomyopathies. We hypothesized that cell-based therapy ameliorates CKD-induced HFpEF.

Methods and Results

Yorkshire pigs (n = 26) underwent 5/6 embolization-mediated nephrectomy. CKD was confirmed by increased creatinine and decreased glomerular filtration rate (GFR). Mean arterial pressure (MAP) was not different between groups from baseline to 4 weeks. HFpEF was evident at 4 weeks by increased LV mass, relative wall thickening, end-diastolic pressure, and end-diastolic pressure-volume relationship, with no change in ejection fraction (EF). Four weeks post-embolization, allogeneic (allo) bone marrow-derived mesenchymal stem cells (MSC; 1 × 10⁷ cells), allo-kidney-derived stem cells (KSC; 1 × 10⁷ cells), allo-cell combination therapy (ACCT; MSC + KSC; 1:1 ratio; total = 1 × 10⁷ cells), or placebo (Plasma-Lyte) was delivered via intra-renal artery. Eight weeks post-treatment, there was a significant increase in MAP in the placebo group (21.89 ± 6.05 mmHg) compared to the ACCT group. GFR significantly improved in the ACCT group. EF, relative wall thickness, and LV mass did not differ between groups at 12 weeks. EDPVR improved in the ACCT group, indicating decreased ventricular stiffness.

Conclusions

Intra-renal artery allogeneic cell therapy was safe in a CKD swine model manifesting the characteristics of HFpEF. The beneficial effect on renal function and ventricular compliance in the ACCT group supports further research of cell therapy for cardiorenal syndrome.

Effectiveness of Stem Cell Therapies in Improving Clinical Outcomes in Patients With Heart Failure

Heart failure (HF), continuing to be a notable cause of morbidity and mortality worldwide, also is a noteworthy economic burden to the patients. Current medical management of HF has poor efficacy to completely arrest or reverse the progression to end-stage disease. As the option of cardiac transplantation remains limited to few patients, the stem cell approach continues to be a promising one in developing a novel therapy in the treatment of HF.

This review attempts to discuss and compare the outcomes of numerous clinical trials that involved treatment of HF of variable etiologies with stem cells of numerous lineages such as bone marrow-derived cells (BMCs), mesenchymal stem cells (MSCs), cardiosphere derived progenitor cells (CDCs), etc. We reviewed articles and randomized controlled trials (RCT) that used stem cells to treat heart failure. The articles and RCT studies were obtained through a search on PubMed and Medline databases and performed using regular and medical subject heading (MeSH) keyword search strategy. A total of 17 trial-based studies, along with other articles that met the aim of the review, were selected. A discussion of the findings from major clinical trials such as the C-CURE, CHART-1, POSEIDON, POSEIDON-DCM, TAC-HFT, and other small scale trials highlights the change in functional and mechanical parameters of HF, namely, left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), end-systolic volume (ESV), 6-minute walking test distance (6MWTD), N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and assessment of New York heart association (NYHA) class of heart failure, and Minnesota Living with Heart Failure Questionnaire (MLHFQ) score to reflect improvement in quality of life (QoL) of patients.

Out of the studies analyzed, the majority reported significant improvements in at least two of the parameters mentioned above. However, more phase three randomized trials are required to compare the efficacy of multiple lineages of stem cells, factoring in molecular and dosage factors to develop a standardized therapy.

Stem cell therapy for dilated cardiomyopathy

BACKGROUND

Stem cell therapy (SCT) has been proposed as an alternative treatment for dilated cardiomyopathy (DCM), nonetheless its effectiveness remains debatable.

OBJECTIVES

To assess the effectiveness and safety of SCT in adults with non-ischaemic DCM.

SEARCH METHODS

We searched CENTRAL in the Cochrane Library, MEDLINE, and Embase for relevant trials in November 2020. We also searched two clinical trials registers in May 2020.

SELECTION CRITERIA

Eligible studies were randomized controlled trials (RCT) comparing stem/progenitor cells with no cells in adults with non-ischaemic DCM. We included co-interventions such as the administration of stem cell mobilizing agents. Studies were classified and analysed into three categories according to the comparison intervention, which consisted of no intervention/placebo, cell mobilization with cytokines, or a different mode of SCT. The first two comparisons (no cells in the control group) served to assess the efficacy of SCT while the third (different mode of SCT) served to complement the review with information about safety and other information of potential utility for a better understanding of the effects of SCT.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all references for eligibility, assessed trial quality, and extracted data. We undertook a quantitative evaluation of data using random-effects meta-analyses. We evaluated heterogeneity using the I² statistic. We could not explore potential effect modifiers through subgroup analyses as they were deemed uninformative due to the scarce number of trials available. We assessed the certainty of the evidence using the GRADE approach. We created summary of findings tables using GRADEpro GDT. We focused our summary of findings on all-cause mortality, safety, health-related quality of life (HRQoL), performance status, and major adverse cardiovascular events.

MAIN RESULTS

We included 13 RCTs involving 762 participants (452 cell therapy and 310 controls). Only one study was at low risk of bias in all domains. There were many shortcomings in the publications that did not allow a precise assessment of the risk of bias in many domains. Due to the nature of the intervention, the main source of potential bias was lack of blinding of participants (performance bias). Frequently, the format of the continuous data available was not ideal for use in the meta-analysis and forced us to seek strategies for transforming data in a usable format. We are uncertain whether SCT reduces all-cause mortality in people with DCM compared to no intervention/placebo (mean follow-up 12 months) (risk ratio (RR) 0.84, 95% confidence interval (CI) 0.54 to 1.31; I² = 0%; studies = 7, participants = 361; very low-certainty evidence). We are uncertain whether SCT increases the risk of procedural complications associated with cells injection in people with DCM (data could not be pooled; studies = 7; participants = 361; very low-certainty evidence). We are uncertain whether SCT improves HRQoL (standardized mean difference (SMD) 0.62, 95% CI 0.01 to 1.23; I² = 72%; studies = 5, participants = 272; very low-certainty evidence) and functional capacity (6-minute walk test) (mean difference (MD) 70.12 m, 95% CI -5.28 to 145.51; I² = 87%; studies = 5, participants = 230; very low-certainty evidence). SCT may result in a slight functional class (New York Heart Association) improvement (data could not be pooled; studies = 6, participants = 398; low-certainty evidence). None of the included studies reported major adverse cardiovascular events as defined in our protocol. SCT may not increase the risk of ventricular arrhythmia (data could not be pooled; studies = 8, participants = 504; low-certainty evidence). When comparing SCT to cell mobilization with granulocyte-colony stimulating factor (G-CSF), we are uncertain whether SCT reduces all-cause mortality (RR 0.46, 95% CI 0.16 to 1.31; I² = 39%; studies = 3, participants = 195; very low-certainty evidence). We are uncertain whether SCT increases the risk of procedural complications associated with cells injection (studies = 1, participants = 60; very low-certainty evidence). SCT may not improve HRQoL (MD 4.61 points, 95% CI -5.62 to 14.83; studies = 1, participants = 22; low-certainty evidence). SCT may improve functional capacity (6-minute walk test) (MD 140.14 m, 95% CI 119.51 to 160.77; I² = 0%; studies = 2, participants = 155; low-certainty evidence). None of the included studies reported MACE as defined in our protocol or ventricular arrhythmia. The most commonly reported outcomes across studies were based on physiological measures of cardiac function where there were some beneficial effects suggesting potential benefits of SCT in people with non-ischaemic DCM. However, it is unclear if this intermediate effects translates into clinical benefits for these patients. With regard to specific aspects related to the modality of cell therapy and its delivery, uncertainties remain as subgroup analyses could not be performed as planned, making it necessary to wait for the publication of several studies that are currently in progress before any firm conclusion can be reached.

AUTHORS' CONCLUSIONS

We are uncertain whether SCT in people with DCM reduces the risk of all-cause mortality and procedural complications, improves HRQoL, and performance status (exercise capacity). SCT may improve functional class (NYHA), compared to usual care (no cells). Similarly, when compared to G-CSF, we are also uncertain whether SCT in people with DCM reduces the risk of all-cause mortality although some studies within this comparison observed a favourable effect that should be interpreted with caution. SCT may not improve HRQoL but may improve to some extent performance status (exercise capacity). Very low-quality evidence reflects uncertainty regarding procedural complications. These suggested beneficial effects of SCT, although uncertain due to the very low certainty of the evidence, are accompanied by favourable effects on some physiological measures of cardiac function. Presently, the most effective mode of administration of SCT and the population that could benefit the most is unclear. Therefore, it seems reasonable that use of SCT in people with DCM is limited to clinical research settings. Results of ongoing studies are likely to modify these conclusions.

Cross-Sectional Survey of Clinical Trials of Stem Cell Therapy for Heart Disease Registered at ClinicalTrials.gov

Objective: It is important to register clinical trials before their implementation. There is a lack of study to evaluate registered clinical trials of stem cell therapy for heart diseases. Our study used the registration information at ClinicalTrials.gov to provide an overview of the registered trials investigating stem cell therapy for heart diseases.

Methods: We searched ClinicalTrials.gov from inception to October 1, 2020 to identify clinical trials evaluating stem cell therapy for heart diseases. These trials were included in a cross-sectional survey and descriptive analysis. The outcomes included start date, completion date, location, status, study results, funding, phase, study design, conditions, interventions, sex, age, and sample size of those trials, as well as conditions, efficacy, safety and samples of the publications. SPSS 24.0 software was used for the statistical analysis.

Results: A total of 241 trials were included. The registration applications for most trials originated from the United States, and the research start date ranged from 2001 to 2025. More than half of the trials have been completed, but few trials have published results (15.62%). The funding source for 81.12% of trials was recorded as “other” because the specific funding source was not indicated. There were 226 (93.78%) interventional studies and 15 (6.22%) observational studies; among all 241 studies, only 2.90% were phase 4 trials. Most interventional studies used randomized allocation, parallel assignment, and blinding. Of the observational studies, 6 were cohort studies (40.00%) and 73.33% were prospective. The most common disease was coronary artery disease (57.68%) and 98.34% included both male and female participants. The sample size included fewer than 50 patients in 58.51% of trials, and only 18 trials (7.47%) lasted more than 121 months. The registered details were illogical for nine trials (3.8%) that included 0 subjects and two trials (0.8%) that had a duration of 0 months (0.8%). In term of publications of the trials, most of the publications of the trials showed efficacy and safety in stem cell therapy for heart disease.

Conclusion: The clinical trials investigating stem cell therapy for heart diseases registered at ClinicalTrials.gov are mostly interventional studies, and only a few are phase 4 trials. Most trials have a small sample size, and few have a duration of more than 121 months. Most of the completed trials did not publish their results, and some of the registration information was incomplete and illogical.

Surfing the clinical trials of mesenchymal stem cell therapy in ischemic cardiomyopathy

While existing remedies failed to fully address the consequences of heart failure, stem cell therapy has been introduced as a promising approach. The present review is a comprehensive appraisal of the impacts of using mesenchymal stem cells (MSCs) in clinical trials mainly conducted on ischemic cardiomyopathy. The benefits of MSC therapy for dysfunctional myocardium are likely attributed to numerous secreted paracrine factors and immunomodulatory effects. The positive outcomes associated with MSC therapy are scar size reduction, reverse remodeling, and angiogenesis. Also, a decreasing in the level of chronic inflammatory markers of heart failure progression like TNF-α is observed. The intense inflammatory reaction in the injured myocardial micro-environment predicts a poor response of scar tissue to MSC therapy. Subsequently, the interval delay between myocardial injury and MSC therapy is not yet determined. The optimal requested dose of cells ranges between 100 to 150 million cells. Allogenic MSCs have different advantages compared to autogenic cells and intra-myocardial injection is the preferred delivery route. The safety and efficacy of MSCs-based therapy have been confirmed in numerous studies, however several undefined parameters like route of administration, optimal timing, source of stem cells, and necessary dose are limiting the routine use of MSCs therapeutic approach in clinical practice. Lastly, pre-conditioning of MSCs and using of exosomes mediated MSCs or genetically modified MSCs may improve the overall therapeutic effect. Future prospective studies establishing a constant procedure for MSCs transplantation are required in order to apply MSC therapy in our daily clinical practice and subsequently improving the overall prognosis of ischemic heart failure patients.

Therapies to prevent post-infarction remodelling: From repair to regeneration

Myocardial infarction is the first cause of worldwide mortality, with an increasing incidence also reported in developing countries. Over the past decades, preclinical research and clinical trials continually tested the efficacy of cellular and acellular-based treatments. However, none of them resulted in a drug or device currently used in combination with either percutaneous coronary intervention or coronary artery bypass graft. Inflammatory, proliferation and remodelling phases follow the ischaemic event in the myocardial tissue. Only recently, single-cell sequencing analyses provided insights into the specific cell populations which determine the final fibrotic deposition in the affected region. In this review, ischaemia, inflammation, fibrosis, angiogenesis, cellular stress and fundamental cellular and molecular components are evaluated as therapeutic targets. Given the emerging evidence of biomaterial-based systems, the increasing use of injectable hydrogels/scaffolds and epicardial patches is reported both as acellular and cellularised/functionalised treatments. Since several variables influence the outcome of any experimented treatment, we return to the pathological basis with an unbiased view towards any specific process or cellular component. Thus, by evaluating the benefits and limitations of the approaches based on these targets, the reader can weigh the rationale of each of the strategies that reached the clinical trials stage. As recent studies focused on the relevance of the extracellular matrix in modulating ischaemic remodelling and enhancing myocardial regeneration, we aim to portray current trends in the field with this review. Finally, approaches towards feasible translational studies that are as yet unexplored are also suggested.

Can Stem Cells Improve Left Ventricular Ejection Fraction in Heart Failure? A Literature Review of Skeletal Myoblasts and Bone Marrow-Derived Cells

Heart failure is a life-threatening condition that affects millions worldwide and is only expected to get worse with an ageing population. Current treatment regimens rely on medical therapy and heart transplantation as a last resort. Stem cells have been undergoing clinical trials worldwide as a hope for a new and safe clinical treatment. Skeletal myoblasts and bone marrow-derived stem cells are two types of stem cells being tested. The objective is to evaluate the efficacy of these two types of stem cells for heart failure therapy. Data were searched in PubMed using both regular and Medical Subject Heading (MeSH) keywords (stem cells, therapy, heart failure) and then filtered using inclusion/exclusion criteria (language, species, publication date, and age). In total, 31 research articles were reviewed (14 clinical trials, four randomized control trials, nine review articles, one case report, one comparative study, one systematic review, and one categorized as a systematic review and meta-analysis). Both skeletal myoblasts and bone marrow-derived stem cells showed mixed results in improving left ventricular ejection fraction in heart failure patients in the majority of studies. Larger studies need to be done to further investigate the efficacy of stem cells as a therapy for heart failure. 

Effect of a dianthin G analogue in the differentiation of rat bone marrow mesenchymal stem cells into cardiomyocytes

Loss of cardiomyocytes due to myocardial infarction results in ventricular remodeling which includes non-contractile scar formation, which can lead to heart failure. Stem cell therapy aims to replace the scar tissue with the functional myocardium. Mesenchymal stem cells (MSCs) are undifferentiated cells capable of self-renewal as well as differentiation into multiple lineages. MSCs can be differentiated into cardiomyocytes by treating them with small molecules and peptides. Here, we report for the first time, the role of a cyclic peptide, an analogue of dianthin G, [Glu²]-dianthin G (1) in the in vitro cardiac differentiation of rat bone marrow MSCs. In this study, [Glu²]-dianthin G (1) was synthesized using solid-phase total synthesis and characterized by NMR spectroscopy. MSCs were treated with two different concentrations (0.025 and 0.05 mM) of the peptide separately for 72 h and then incubated for 15 days to allow the cells to differentiate into cardiomyocytes. Treated cells were analyzed for the expression of cardiac-specific genes and proteins. Results showed significant upregulation of cardiac-specific genes GATA4, cardiac troponin T (cTnT), cardiac troponin I (cTnI), cardiac myosin heavy chain, and connexin 43 in the treated MSCs compared to the untreated control. For cardiac-specific proteins, GATA4, cTnT, and Nkx2.5 were analyzed in the treated cells and were shown to have significant upregulation as compared to the untreated control. In conclusion, this study has demonstrated the cardiac differentiation potential of [Glu²]-dianthin G (1)-treated rat bone marrow MSCs in vitro both at the gene and at the protein levels. Transplantation of pre-differentiated MSCs into the infarcted myocardium may result in the efficient regeneration of cardiac cells and restoration of normal cardiac function.

Consensus document: management of heart failure in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a known predisposing factor for heart failure (HF). The growing burden of these two conditions and their impact on health of the individual and on society in general needs urgent attention from the health care professionals. Availability of multiple treatment choices for managing T2DM and HF may make therapeutic decisions more complex for clinicians. Recent cardiovascular outcome trials of antidiabetic drugs have added very robust evidence to effectively manage subjects with this dual condition. This consensus statement provides the prevalence trends and the impact of this dual burden on patients. In addition, it concisely narrates the types of HF, the different treatment algorithms, and recommendations for physicians to comprehensively manage such patients.

N-cadherin overexpression enhances the reparative potency of human-induced pluripotent stem cell-derived cardiac myocytes in infarcted mouse hearts

AIMS

In regenerative medicine, cellular cardiomyoplasty is one of the promising options for treating myocardial infarction (MI); however, the efficacy of such treatment has shown to be limited due to poor survival and/or functional integration of implanted cells. Within the heart, the adhesion between cardiac myocytes (CMs) is mediated by N-cadherin (CDH2) and is critical for the heart to function as an electromechanical syncytium. In this study, we have investigated whether the reparative potency of human-induced pluripotent stem cell-derived cardiac myocytes (hiPSC-CMs) can be enhanced through CDH2 overexpression.

METHODS AND RESULTS

CDH2-hiPSC-CMs and control wild-type (WT)-hiPSC-CMs were cultured in myogenic differentiation medium for 28 days. Using a mouse MI model, the cell survival/engraftment rate, infarct size, and cardiac functions were evaluated post-MI, at Day 7 or Day 28. In vitro, conduction velocities were significantly greater in CDH2-hiPSC-CMs than in WT-hiPSC-CMs. While, in vivo, measurements of cardiac functions: left ventricular (LV) ejection fraction, reduction in infarct size, and the cell engraftment rate were significantly higher in CDH2-hiPSC-CMs treated MI group than in WT-hiPSC-CMs treated MI group. Mechanistically, paracrine activation of ERK signal transduction pathway by CDH2-hiPSC-CMs, significantly induced neo-vasculogenesis, resulting in a higher survival of implanted cells.

CONCLUSION

Collectively, these data suggest that CDH2 overexpression enhances not only the survival/engraftment of cultured CDH2-hiPSC-CMs, but also the functional integration of these cells, consequently, the augmentation of the reparative properties of implanted CDH2-hiPSC-CMs in the failing hearts.

Mesenchymal Stem Cells: The Past Present and Future

The biomedical applications of mesenchymal stem cells (MSCs) have gained expanding attention over the past three decades. MSCs are easily obtained from various tissue types (e.g. bone marrow, fat, cord blood, etc.), are capable of self-renewal, and could be induced to differentiate into several cell lineages for countless biomedical applications. In addition, when transplanted, MSCs are not detected by immune surveillance, thus do not lead to graft rejection. Moreover, they can home towards affected tissues and induce their therapeutic effect in a cell-base and/or a cell-free manner. These properties, and many others, have made MSCs appealing therapeutic cell candidates (for cell and/or gene therapy) in myriad clinical conditions. However, similar to any other therapeutic tool, MSCs still have their own limitations and grey areas that entail more research for better understanding and optimization. Herein, we present a brief overview of various pre-clinical/clinical applications of MSCs in regenerative medicine and discuss limitations and future challenges.

Function Follows Form - A Review of Cardiac Cell Therapy

The investment of nearly 2 decades of clinical investigation into cardiac cell therapy has yet to change cardiovascular practice. Recent insights into the mechanism of cardiac regeneration help explain these results and provide important context in which we can develop next-generation therapies. Non-contractile cells such as bone marrow or adult heart derivatives neither engraft long-term nor induce new muscle formation. Correspondingly, these cells offer little functional benefit to infarct patients. In contrast, preclinical data indicate that transplantation of bona fide cardiomyocytes derived from pluripotent stem cells induces direct remuscularization. This new myocardium beats synchronously with the host heart and induces substantial contractile benefits in macaque monkeys, suggesting that regeneration of contractile myocardium is required to fully recover function. Through a review of the preclinical and clinical trials of cardiac cell therapy, distinguishing the primary mechanism of benefit as either contractile or non-contractile helps appreciate the barriers to cardiac repair and establishes a rational path to optimizing therapeutic benefit.

Update on heart failure management and future directions

Heart failure (HF) is an important cardiovascular disease because of its increasing prevalence, significant morbidity, high mortality, and rapidly expanding health care cost. The number of HF patients is increasing worldwide, and Korea is no exception. There have been marked advances in definition, diagnostic modalities, and treatment of HF over the past four decades. There is continuing effort to improve risk stratification of HF using biomarkers, imaging and genetic testing. Newly developed medications and devices for HF have been widely adopted in clinical practice. Furthermore, definitive treatment for end-stage heart failure including left ventricular assist device and heart transplantation are rapidly evolving as well. This review summarizes the current state-of-the-art management for HF and the emerging diagnostic and therapeutic modalities to improve the outcome of HF patients.

[Changes of two-pore K+ channel TASK-1 in diabetic myocardial injury in rats]

OBJECTIVE

To investigate the changes of the two- pore K⁺ channel TASK-1 in diabetic rats with myocardial injury.

METHODS

Thirty-six SD rats were divided into normal group (N), diabetes at 4 weeks (DM 4W) group, and diabetes at 8 weeks (DM 8W) group. The cardiac functions of the rats were determined using cardiac ultrasonography, and the body weight and heart weight of the rats at different time points were measured to calculate the heart/body weight ratio (HW/BW). Myocardial fibrosis in the rats was assessed using Masson's staining. The protein expression of TASK-1 in the myocardium was detected using Western blotting. Whole- cell patch clamp technique was used to record the action potential duration (APD) and twopore domain potassium channel TASK- 1 current in acutely isolated rat ventricular myocytes. meanwhile, The inhibition of TASK-1 current was observed by the TASK-1 specific inhibitor ML-365.

RESULTS

Compared with the normal group, the diabetic rats showed significantly increased HW/BW (P &lt; 0.05), end- diastole left ventricular diameter (LVIDd), end- systolic left ventricular diameter (LVIDs), and TASK-1 protein expression, with obviously decreased left ventricular diameter shortening rate (FS) and ejection fraction (EF) (P &lt; 0.01). Masson staining showed that in diabetic rats, the collagen fibers were thickened, interwoven into a network with uneven arrangement and increased deposition. Compared with DM 4W group, the rats in DM 8W group exhibited progressive increases in LVIDd, LVIDs, HW/BW, and TASK-1 expression (P &lt; 0.01 or 0.05); FS and EF were further decreased (P &lt; 0.01). Masson staining showed worsened morphological changes of the myocardium with increased deposition. Compared with that in the normal group, the current of TASK- 1 in diabetic rats at 8 weeks was significantly reduced (P &lt; 0.01) and the duration of action potential was extended (P &lt; 0.05). The TASK-1 current was successfully inhibited by ML-365.

CONCLUSIONS

Diabetes can induce myocardial fibrosis and aggravate myocardial injury possibly in relation to changes in the protein expression and current of the two-port potassium channel TASK-1.